Hrm... 5300? I didn't know there was such a thing... is it a UK only model, or something?
I'm assuming it's the standard 5xxx form factor when I explain this.
The time issue is probably a battery issue; the battery is a large black thing on the motherboard, probably on the upper-right corner, if you were looking at the "front" of the motherboard (if the front were the same end that was the front of the computer).
To install more RAM, you need to take three screws out of the back panel, unclip it from the bottom, and pull back.
Pull the handle down, and pull the motherboard out of the machine. From your current viewpoint, the RAM slots are off to your right - you can't miss them.
I can post pics relevant to a 5500 if you want me to.