I've done many u joints over the years, and wouldn't pay somone to do somthing so simple myself. A press makes it easier, but a vice and a hammer work fine. If yuo pull the slip yolk apart, make sure you line the u joint caps back up (this is why you mark it). If you don't slide the slip yolk apart, no worries. Definetly opt for the better u joints with grease zirks, and then grease them regularly.