Ah, the oil filter. Ha ha ha. You have no idea what 7th circle of hell you are getting into.... : - )
1) Get the front of the car up on axle stands, nice and high, you're going to the back of the engine.
2) Wriggle under the car till you are looking up at the back of the block. There, on the right hand side is the oil filter.
3) No ordinary garage tool will remove it. I had a chain wrench - no room. I had a top clamp - certainly no room.
4) Depending on whether you have a CF1, 2 or 3, you may find a load of pipework has to be unbolted (it will be seized) and moved away. From memory it is PAS pipework.
5) I now have a Facom band wrench (£30, ebay) that will get it off instantly, but the only answer for me at the time was to stick a screwdriver through the filter and twist it off. Remember you are lying directly under it at this stage, you are going to get covered, make sure it is cool.
6) Put new filter on, replace pipework, go have a shower.
Sump plug - on the edge of sump, can't remember where, but it is obvious.