I won't say I know how to increase cholesterol, but here is a list of cholesterol high foods.

Egg Yolk
Caviar aka Fish Roe
Foie Gras and liver pates
Butter
Shrimps/prawns
Oil packed fish e.g. canned sardines, mackerel
Cheese
Shellfish
Crab cakes
Heavy whipping cream
Crayfish
Veal liver
Octopus and squid
Pork ribs