This is a pretty vague question.They are several steps,tools and equipment needed to replace brakes. Do you have tools? Are you replacing rotors? (since the pad fell out, you probably need rotors) Does it need hardware?
I can assure you, if you attemp to drive it, the damage and repair cost will keep going up.
Well, its pretty easy.
unbolt 2 14mm bolts that hold caliper to pad holder, remove caliper, Squeeze piston into caliper with large pliers, vise grips or special tool.
Use a screwdriver and remove old pads
Transfer over any shims from old to new pads
Install new pads into pad holder
Slide caliper back over pads and install and tighten 2 14mm bolts.
If you have problems, just post up and I'll get ya through it.
Are you doing it today?
You'll need a very large pair of pliers to push caliper piston in, so make sure you have that before you start.
The pliers should be fine.
Since you are not replacing or machining rotors, get the pads wherever easiest
Sry, I cannot email you directions, you'll have to print screen.
I will around most of the day and evening, just post up with questions and I'll get back to you ASAP.