As long as they don't have any nicks which can be the start of a tear, they're pretty stretchy and should go on without any problem. I installed hundreds of these when I was the east coast campy service technician.
It helps to warm the hood in hot tap water, about 120-130F. Slide it on over and around the brake and shift levers while the lever is still mounted on the bar. I use a small rag to improve my grip on the wet rubber, and gently work it over the lever into place. Be sure to get all the locator tabs into the recesses where they belong to keep the hood from moving when you ride.
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.