Both the vertical and horizontal rubber caps that the belt cover connect to have dried and cracked on my 2000 M750. The replacement parts available, but how difficult is it to replace these? It appears that the cam pulleys need to be removed to get to the rubber caps.
Has anyone else been down this road and able to offer up any advice?
Others have. There are some special tools required to remove the pulleys. There are pulley holders and castle nut sockets. Some have made castle nut socket by cutting an appropriately sized socket and some have used an old cam belt with vice grips to hold the pulley .
Use the search function here and see what comes up as there were quite a few threads on this iirc. Not an uncommon issue on older bikes.
The cam belt cover bolts don't need much torque at all and people often don't lube them.
Is this the correct pulley holder and castle nut socket for a 2000 M750?
https://www.amazon.com/Ducati-Pulley-Pantah-Valve-Drives/dp/B005CW9SO0
They look correct but check they match your model to be sure as there are more than one type. I have those and also some from Desmotimes. So two sets of each type.