You don`t say what engine is in yours,1.9 or 2.0l hdi, but if I remember correctly they are much the same,remove the o/s lower engine cover for access and think the adjuster is next to the alternator,you must slacken the hex bolt in the middle of the pulley and the same hex size bolt from below to adjust,think they are 6mm,hope this helps,sorry if any information is wrong.
cdc, April 2015