How do I get this rounded bolt out?!

I'm with Oz on that, the plug does'nt look like it's been connected to anything. It would be pretty clean inside if it had been plugged into something.

Well as long as its not something that I've knocked out!!

Well done on completing the pump change!However it would have been wise to replace the 'P' Gasket also,it has a habit of leaking as it gets disturbed when the lower 3 bolts securing the water pump to the block are loosened.Refer to this article to replace itLand Rover UK Forums

As an aside and for future reference(after looking at your tools)I would be inclined to use a 6 point socket as these type get a better hold on the bolt head to begin with....a smudge of copper grease on the bolts then make it easier if they have to be removed again...

Thanks guys. I will be getting new tools as I go along. This is the first thing mechanical I've ever done and the socket set was loaned to me by a friend so I need to buy some anyway....

I think I got myself all a bit confused... I thought the big gasket that I put on with the new water pump was the P gasket.. On further inspection of a picture that Richard Martin sent to me it would appear that I should have carried on taking things off to get at the P gasket further back. D'oh!

Its not leaking for the moment though so shall I leave it as it is or take it all apart again and replace the P gasket?? I feel really stupid