I replaced the timer, which was pretty easy. Then I replaced the solenoid as well as the armature and linkage. The old one had basically melted and the plastic fused to the armature. It was pretty easy to get the old one out- although that electrical plug did NOT want to come out. Felt like I was going to break it, but eventually got it out. You will need a fairly short screwdriver to get in the small space. The hardest part of getting the new one in was that little "E clip," but I got it eventually.
Since then it's been running great!