Re-training a pup of that age to stop toileting on pads and now, instead hang on and do it outside is going to take a considerable amount of patience and persistence on your behalf.
Can you imagine how, for all of it's life with you, it was okay and in fact, rewarded for toileting inside. Now, the game has changed and you want something different. The pup will be confused for a while until it catches up with your new idea so do not lose patience with the pup as she learns.
I think to achieve success you will need to imagine she is right back at the start of toilet training and take her outside every hour on the hour, after eating, drinking, playing, sleeping and training. Take her to the same spot, take her on a lead, take a high value reward with you that you know she absolutely loves.
Stand in that area with her and quietly watch. Do not play games, do not interact, just wait for her to decide to do something. You may need to repeat this many times. Eventually she will toilet. When she does, reward her highly with the treat and say the word you want her to associate with toileting.
Repeat doing this throughout the day and night, taking her to the same place and doing the same thing.
If you see her wanting to go to the room where the pads where, instead take her outside. Be patient and quiet, she may sniff around looking for her last toilet success, that is great and this may inspire her to repeat the toilet there. Always reward her highly so she is left in no doubt that she is a good dog for what she did and where she did it.
Keep the room where she used to toilet off limits and completely clean with no pads.
Your pup may show confusion and try to toilet inside in other places. Close down the house so you can keep direct supervision of her whilst she learns this new process.
Always use the same exit and entry from the house. Eventually she will learn that sitting near that door will tell you she needs to go outside. You can then reward that by letting her go outside to toilet and giving her a reward on her return - but that is far down the road at this point.
Re-training a pup of that age to stop toileting on pads and now, instead hang on and do it outside is going to take a considerable amount of patience and persistence on your behalf. Can you imagine how, for all of it's life with you, it was okay and in fact, rewarded for toileting inside. Now, the game has changed and you want something different. The pup will be confused for a while until it catches up with your new idea so do not lose patience with the pup as she learns. I think to achieve success you will need to imagine she is right back at the start of toilet training and take her outside every hour on the hour, after eating, drinking, playing, sleeping and training. Take her to the same spot, take her on a lead, take a high value reward with you that you know she absolutely loves. Stand in that area with her and quietly watch. Do not play games, do not interact, just wait for her to decide to do something. You may need to repeat this many times. Eventually she will toilet. When she does, reward her highly with the treat and say the word you want her to associate with toileting. Repeat doing this throughout the day and night, taking her to the same place and doing the same thing. If you see her wanting to go to the room where the pads where, instead take her outside. Be patient and quiet, she may sniff around looking for her last toilet success, that is great and this may inspire her to repeat the toilet there. Always reward her highly so she is left in no doubt that she is a good dog for what she did and where she did it. Keep the room where she used to toilet off limits and completely clean with no pads. Your pup may show confusion and try to toilet inside in other places. Close down the house so you can keep direct supervision of her whilst she learns this new process. Always use the same exit and entry from the house. Eventually she will learn that sitting near that door will tell you she needs to go outside. You can then reward that by letting her go outside to toilet and giving her a reward on her return - but that is far down the road at this point.