Get a cd, cdrom, PS2, or whatever cleaning kit from any store around town. They're cheap. If it doesn't solve your problem, then it will probably cost you more to fix it from a technician.
ie. If you pay $40 minimum to fix an old 2 year old cdrom, it will probably fail again and you could probably buy a new cdrom which is faster and has a warranty. My ex gf had a 4x cdrom in her old machine and it just stopped reading cds cause the laser was out of allignment. She blamed me and wanted it fixed, I said screw it and bought a new one cause there's less hassle and price. Why make yourself more trouble than it's worth?
You might not have alot of bucks cause you're young, but what are you going to do? If it doesn't work, unless you're a tech who knows what he's doing, I wouldn't try fixing it yourself. Save up your pennies and buy a new one or ask for one for a b-day, or whatever. Hehe Shouldn't you be in class now?