hi guys new on here and need some advice i have just bought an a3 1.8t on a y reg its done 137000 and i know that they suffer with the oil pick up getting blocked so im giving it a good going over ive changed all filters and plugs and now droped the sump to give it a good clean ive ordered a new pick up pipe but my question is should i replace the oil pump while ive got the sump off and if so do i just undo the three bolts and pull back on the tensioner to slacken the chain

thanks in advance