DIY jobbie or skilled mechanic? Had a few nasty “slips” recently and been as cassette and chain is reasonably new, I’ve swoppedd my rear wheel and it still slips but only in the middle or inner ring it must be the front rings surely….?
So is it easy to change the chainrings? Any special skill or tools required or can any numpty do it?

Easy

DIY jobbie.

Get one of these http://www.probikekit.co.uk/bicycle-tools-and-maintenance-nc/park-tool-bbt-9-bottom-bracket-tool/10772157.html if it’s Hollowtech 2 because you need to remove the little ‘tensioner’ plug on the NDS. Tho you can do it with pointy pliers usually, it’s not meant to be super-tight.

easy if you have the right tools. I’d much prefer to spend money on tools and diy than pay for a mechanic to do it. Get to know how your bike works and it’s free if you need to do it again

You may need a little tool thing to undo the chainring bolts (Shimano TL FC-20.)

Edit: Park tools do one too.

+ once the cranks are off, changing the BB is just another 5 minutes, so you’ll know how next time you need to do that too

park tool website has some really good guides to home spannering.