Do you mean:-
The large belt that drives the water pump, power steering pump, alternator OR the other belt that drives the air con pump?
The large drive belt doesn't seem to be too bad to change. Bottom engine undertray off, remove o/s front plastic wing protector panel (lower), you will then see the pulleys and belt.
Pull back the tensioner pulley with a spanner and HOLD it away from the belt. Remove belt. Then you can get to the other belt that drives the air con pump. This too has a tensioner. Need to slacken with spanners here as in old fashioned fan belt style. Fit new belt. Tension up,
Refitting large belt is as they say - the reverse of removal. Locate it around all the pulleys etc then SLOWLY release tensioner pulley so it contacts belt. Don't let the pulley twang back onto the new belt!
Stupid question time....
what size is the tensioner pulley nut, .... tried 19mm .... so need go out and purchase correct size...
thankin anyone kindly ...