I wouldnt get those 'HID' bulb on ebay that are selling for around a fiver. They are not HID buld, but just normal bulbs with a blue/white tint to them. They are very poorly made too, had a set fitted on my old car, and they blew withing 2 weeks. Bought another set, they blew within a week. Just went back to the old bulbs in the end.
Proper HID kits can cost up to 200 notes and you need the right sort of headlight units for them too, which the puma does not have. I wouldnt bother myself. Just get some nice new bulbs (the super bright ones from halfrauds aint bad) and make sure the lens/plastic covers are nice and clean.
To Lawrence, changing bulbs is easy really. Get the bonnet up, and remove the front grill (about 4 screws i think) then each headlight unit is another 3 screws i think. Whip out the whole headlight unit and replace bulb. All done.