trying to replace idler pulleys
 

I am trying to replace both idler pullys on my 2000 land rover disco II,
but its not going well for me.I cannot get the bolts to budge, ive used 13mm socket with a breaker bar,ive used 13 mm box and open end wrench

nada.nothing,no movement,

what am i doing wrong!

any advice your willing to give would be appreciated

I recently did mine too and had similar issues. All I can say is try to soak them with a penetrant and let it soak overnight. If you can't get it loose with a wrench don't try to pry it off otherwise you will definitely break something. The new WD 40 rust release seams to work good. I used it on all my exhaust bolts and didn't break a single one. Be sure to soak the heck out of it and let it sit for a while.

PB Blaster. Soak and wait.

You should replace all 3 at the same time which includes the pulley on the belt tensioner.