My 1993 Jeep GC is hard to start. I always have to push on the gas to get it to rollover, but if I start my jeep then drive someplace and shut it off for a little while its a lot easier to start afterwards. I took it to a mechanic and he said that I need to replace one of the fuel injectors b/c it has a slight leak, which is lowering my fuel press.? Does this sound right? where can I find instructions to replace a fuel injector? Is it hard? my dad is a retired mechanic, but has never done one before. Any advice??

That sounds right if it is leaking externally. Smell or look for gas around each injector.