I have a small fuel leak, how do I replace the o rings on injectors? on 1991 Cadillac DeVille

Smell gas but can't see any leak, nechanic told me needed to replace fuel injectors, but I think new o rings would do the trick. What is the vacuum hose possibility?

Asked by for the 1991 Cadillac DeVille
why dont you believe your mechanic?? it is common for them to leak and need to be replaced.

vacuum hose, no.

what motor do you have??