I watched Fletcha install mine and if someone (ar achem....Fletch) was to briefly explain how to install it I would say It's a pretty straight forward job....haha

Sealed beams just means the casing behind the light is all sealed up so no water / mud gets in.

Fletcha just siliconed the back of my lights but after going through a large mud hole I did fill up one of the lights with muddy water as we forgot to seal up one of the lights which stains the inside and is a nightmare to get out again....