Q: Need to set up an old Mac Mini and restore from backup

I have a weird question.   My husband, who is quite old and disabled, had his old Mac Mini die.  Well a friend gave us a "new" old mini so he could get back up and running but I need to do two things.  One is I need to get all programs they had off it  because it is way too loaded for an old mini without intel.   I also need to keep it simple for the hubby.   The second thing I need to do is restore all his stuff from the Time Capsule.    The mini has the former user's stuff on it and I would like to wipe everything so that I get a it down to the set up assistant so I can  then have it take all the data off the Capsule and put it in the mini.  Is there a way to do that????   Thanks

PS   It has OS 10.5 on it.