[cypher]

Try not to worry too much about the vet trip, if you're feeling anxious he will probably pick up on it which won't help.
If you have a vet who's used to handling small hams it really shouldn't be too stressful at all & even if he is stressed a bit by it all a little quiet time to settle down afterwards with a nice treat usually does the trick!

Is he used to being in his carrier? If he is that will make things easier for him, put some substrate from the cage in so it smells familiar to him & he should be fine.
If he isn't used to it you could try putting him in there for a short period a few times, maybe hide a few seeds in the substrate for him to dig around for so it becomes more like play than stress!

I really don't know why but Russian hams nails seem to grow much faster than other hams & most of the usual things people suggest for wearing them down are rarely enough although they do help a bit so either trimming them yourself or getting the vet to do it is usually inevitable with them.