bigvegan

OK, assuming you're being serious.

1) Take your bike to a bike shop /bike mechanic / bike co-op, tell them what you want to do, let them do it, and pay the appropriate (largish) amount of money. They may snicker, and you may spend, but this will be the most hassle free way to achieve your objective.

2) Since you're probably full of youthful enthusiasm and minimal common sense, you're not going to do that, so here are the things you need to be aware of:

A. The Giant Compact Road SL is a great bike, but unfortunately it has vertical dropouts for the rear wheel. This means that if you want the sexy singlespeed / fixed gear look, you're either going to have to do a lot of work finding the proper chainring / freewheel combo, and maybe use a half-link, and get very lucky, or you're going to have to spend much dinero getting a rear wheel with an eccentric hub to allow you to space things properly. Otherwise, you're going to have to keep your existing derailleur, or buy a chain tensioner, which will leave you with none of the aesthetics of a singlespeed, and none of the functionality of a geared bike.

B. You'll need to unwrap the handlebars before putting brake levers. You can either put road levers on the curves of the drops, or you can put cross levers on the flat part of the handlebars, or both.

C. Wheels. It sounds like you've bought the wrong size wheels. 700s will fit on 27" wheel frames (you may need longer reach brakes) but not vice versa.

To sum up. Leave your bike alone and ride it with gears, and then go to bikesdirect.com and buy a cheap singlespeed, or go to craigslist and buy an old road bike with horizontal dropouts to convert to singlespeed, and have someone who knows what they're doing either do the work or help you do this. Either option will be cheaper and less frustrating for you.

Good luck.