i dont know what my oil pressure should be. when i first start it(its 10 degree weather in MA right now), the pressure is around 55psi. once it is good and warmed up it hangs around 13-20psi even on the highway. i know the inside of my motor is pretty sludgy as i recently replaced my valve cover gasket and inspected the cover. i am positive i will at least need to replace the screen. at the moment it is still my daily driver and it is extremely cold outside(and thus in my garage also) so i do not want to do this job twice. if replacing my oil pump is a raging pain in the ass and could easily destroy my engine then i will let it slide. if it is a simple job but the parts are kind of pricy, i'll do it anyway for the piece of mind.

1)could someone explain the steps involved

2) what parts are recomended(high volume, brand, tools, etc)

3)should the screen tube be tacked to the pump assembly?