To remove your glow plugs, clean the top of your engine and:
1. Find the bus bar on the intake side of the valve cover.
2. Remove the tiny nuts holding the wire to the bus bar and the bus bar to the glow plugs. It's like 6 or 7 mm.
3. Unscrew the glow plugs with a deep socket. It's 10mm maybe.
4. After they are clear of the threads they are still a tight fit. Pull them out like a wine cork.
Crank it until you're convinced the cylinders are dry, reverse the process and start it up.
Pics attached (the nuts and washers above the plugs are from the valve cover, just ignore those).