J.G.
My son is also 4. We have struggles like this from time to time, but the biggest one is getting dressed in the morning when we have to go to preschool. He'd rather stay in his pj's all day. I try letting him know that he has 5 minutes to get dressed (when he really has 10) and then giving him a 2 minute warning. This has helped quite a bit, but he still likes to waste time. I think a big part of it is wanting to do things on his own and trying to assert his independence.
Just keep working with him and loving him. Be as positive as you can other times of the day to really establish a good relationship. That it will make these struggles a little easier to deal with for both of you.