Hoe do I replace valve cover gasket & spark plug tube gasket? on 1996 Nissan Sentra

Discovered oil on spark plugs. Valve cover is plastic and attempted removing old gasket from tubes, crumbled,
New ones look to big
to fit.

Asked by for the 1996 Nissan Sentra
double ck with parts house you may have the wrong gasket
1 more answer
HOE, wrong gaskets