how do I replace speakers on 1992 accord ?

Hello,

My 1992 Accord is still running.  It still has the original stereo, yet
the 
speakers now play distorted sound, so I would like to replace them.  I
have 
2 speakers in the doors and 2 speakers in the back.  They are 6.5".  How
do 
I replace the speakers?  Thanks.

T.I.