So,my mom got three rats about 2.5 years ago she loved them very much trained them and took really good care of them but then two of them passed away and she was left with one when this happened my mom was going through some stuff and stopped playing with him and pretty much neglected him he still got food and water but his cage only got cleaned about once or twice a month, despite what he's been through he's still pretty kind doesn't bite or anything he has forgotten all of his training though and is a little shy i was wondering if any of you guys have any tips for training,feeding,cleaning,ect.

Well clean the cage weekly, and spend time playing with him. If his two compainions passed on a short time ago you might and I stress might be able to introduce a new buddy to him. Rats are very sensitive creatures.

Try bonding with him by letting him sit on your shoulder and explore around you. Treats will help. My rats loved fresh fruits and veggies as a treat. They also liked various seeds and nuts.

I don't own them anymore but years ago I kept (male) rats. They are really social creatures and if yours was used to the company of others, I'd second getting a buddy immediately. I never had an issue introducing new rats to my old ones, so I wouldn't worry too much about that (but I did have one that I was never able to really get used to me, I had him from the time he was pretty little til he passed away from old age and he hated me the entire time), but if you don't want another rat I'd consider rehoming to a home with rats. Like Hawkeye said they are sensitive and he is probably pretty lonely and loneliness can be really stressful and/or depressing to them, which of course will be detrimental to his longevity. I agree with lots of treats, mine would always get really excited for snacks. So that would be a great way to bond with him. Training, I'm not sure I'd worry too much about that at his age, he's pretty elderly at this point if he's 2.5. I'd just get him a friend, play with him, and stuff him full of goodies and he should be a very happy rat.