My friend I guarantee you can do this yourself. It's not hard. You will need a socket for the stem nut & a set of metric allen wrenches. Some good (I like to use high temp) bearing grease. If you plan to do the lower bearing your going to need a lift to get the bike up in the air. You can't get the bearing off the lower tree unless you press it off and then back on. I do it while it's attached. It's a little harder cause your really have to push it in there to pack it. As for your fork oil. I don't think I would bother with that. (that's just my opinion) Unless you just have ungodly amount of miles on that bike??

My first question to you about your wobble though is this?
Have you checked your tire pressure? And what is the condition of your front tire? When your on the bike and holding it up and you let go of the handle bars to they fall to the side hard. You might have to give one side or the other a little very little push and then let go again to see.