Has anyone changed the coolant on a facelift yeti 2.0tdi 170 bhp or simiar. Doing it at the weekend and wanted to see if anyone has any tips

Err? Why? Modern anti-freeze/anti-corrosion stuff doesn't go "off" like the old stuff did.

Thought it was still reccomended to change it every 3 years

Not that I know of, and it certainly has never been offered to me by any of the dealers, at any time.
And I can't see it in any service schedules.

I haven’t changed the coolant in any of the cars I’ve owned, and frankly never had a need to top it up.

IIH, the coolant gets changed when you replace the cambelt and waterpump, which, depending when you bought the vehicle, is every 4 or 5 years. 

 

Just had mine changed for the second time last week. 

I will leave it then. One less job