Problem Playing Any Disc

hey guys ive got a panasonic SC-RT30 or to be exact and SA-RT30 but panasonic somehow say its an SC-RT30
well anyway for some reason it wont play any disc i put in it
no matter what the drive dont spin up or anything
it does make a noise and ive taken the top of the drive off and the lense is bouncing against the spindle well i think the lense is good as its on ie it shows its red glow from the laser
but for some reason it wont spin
and as it has past its 1 year warranty panasonic want £250 to fix it and im thinking what the hell cant i just replace the drive myself
any ideas guys