If you have to replace your HG, you'll have to take off the accessory brackets anyway. They are in part bolted to the heads. You would be best off, starting from the top and working down. I took off all the accessories before I started with the acc. brackest, with the exception of the P/S pump. I left that on. I didn't remove the brackets from the car, but leaned them forward so I could get to other stuff. Bad thing for me is that I didn't replace the HG, just resealed the upper 1/2 above them. Now I may have to replace them anyway... Good luck and if you can, get a shop manual. It will help out a lot. Especially if you have limited mechanical experience, like me.
Just a though for you about checking for coolant in the oil. You can loosen your drain plug to the point where oil will start coming out. If there's coolant in there, it's heavier than the oil and will be on the bottom of the oil pan. That is why it wil ruin the bearings...oil pick up is pumping coolant instead of oil. You'll be able to tell if there is any coolant in there real fast. Just don't forget to tighten it back up...