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It isn’t hard.
Just take your time, highlight the pulley markings and pointers with typex, take a few photo’s of everything before you slacken the tensioners, and check twice after hand cranking the engine a couple of turns before putting the belt covers back on.

Are you changing the tensioner bearings too? Those do wear/seize/get notchy after a while.

Also, bear in mind that the markings probably won’t align exactly with the pointers. The teeth on the toothed belt have to fit in the slots for them, so there are no half tooth options. Just go with the one that looks most like what was there before you started.