What gen MR2 do you have? If memory serves, it's a 2nd Gen.
It won't be as easy as you make it sound. I doubt you will be able to keep the belt snug enough against the 2 cam gears and crankshaft gear without it slipping a tooth or two.Especially when it comes time to bolt the cam gears back into proper position.
Make sure you bring #1 cylinder to TDC before beginning. Mark the position of cam and belt teeth .Try not to let the bottom of the belt slip off the crankshaft gear.
Whatever you do, don't loose or drop the cam gear pins into the timing cover.
Here's a few pics of the inside. Click on the drop down in the "Service How To's".
Camseal replacement