I don't know what kind of skimme ryou have, but usually every 6 months for the basic gear is ok. Wipe out the part you can reach with a paper towel, and of course empty the cup weekly.
If you have 45 lbs of live rock, you don't actually need a filter. What you do if you do have one and want to clean it is to swish the pad and other media around in a bucket of non-chlorinated water [your old tank water that you're about to throw out will work] until you get the crud out.
1. the more often you do this, the more methodical it will get. It takes some time to learn to choreograph your moves as a team to avoid leaving a pump on when it should be off, etc. Just be calm and laugh about the oopses.
2. when disassembling something, clear a workspace and carefully lay parts down---farthest away, first thing taken off, next farthest, next thing, etc. That way when you go to reassemble it, you will know exactly in what order to assemble the pieces.
Fastest way to do a water change: a maxijet pump of about 800 level, with a hose attached, plus a 5 g bucket other than the one you're mixing salt in. Drop pump in, with hose in bucket, drain; set that bucket aside to wash filters. Put pump in new saltwater bucket [you can get these white polystyrene buckets at Lowe's paint department] and put hose end in tank; turn on pump.
Beware: a pump left in the tank wtih the power off will siphon more water even when off. Be careful to lift pump free of the water expeditiously when you unplug it. There are extension cords with off switches that help simplify the choreography of this operation.
Clean your skimmer every few months; your filter media and your powerhead sponge shield every week---do not remove your filter or powerhead, just the media and sponges---and have plenty of clear workspace for both of you to move and work. Trust me: this can be fun. You're just not there yet.