If your Xbox works correctly for now, I don't personally see a purpose in trying to 'fix' it. You can take the heatsinks off and apply better paste, and clean out the dust inside, but other than that I wouldn't change anything if it's working great right now. However, if it is giving you the RRoD, then here is my story:
My console was RRoD when I bought it from my roommate last year. It worked when he got it from a friend, and I never tried til about 2 months after I bought it from him. It RRoD right off the bat, so I took to the internet to figure out my options. I quickly stumbled on
THIS tutorial. I followed the instructions, and now it works perfectly. One thing I did differently, I didn't want to go through the hassle of drilling holes so I didn't, and put the screws (half-inch in length) directly through the motherboard and heatsinks.
Needed for this task:
#10-24 x 1/2-inch screws#10 lock washers (make sure whatever washers you get are thin like these, since two pairs of screws in the motherboard will be very close and most washers are too wide to fit)
ArctiClean (with AS 5)
And lastly, T10 and T8-sized Torq Screwdrivers, included in
THIS set I used.
I will say, as a heads-up to anyone who does this, when you're done putting the bolts and washers on, put your Xbox back together completely before testing it. It sounds like a pain in the butt, but when I did this method, for whatever reason, my Xbox refused to work until I got tired of it taking up space and put it all back together to get it out of the way. After it was back together, I tried to turn it on just for the heck of it, and it has worked flawlessly ever since. The screw heads are a hair too tall, though, and so the motherboard sits about 2mm too high, and as a result the DVD drive tray will not open unless my Xbox is laying down on its side - if it's standing up it won't open.