Wasn't looking forward to this but turned out very easy in the end.
1. Place rear on ramps and secure.
2. Remove plastic engine undertray.2a. Remove plastic vapor tank.IMG_20210508_0001.pdfIMG_20210508_0001.pdfIMG_20210508_0001.pdfIMG_20210508_0001.pdfIMG_20210508_0001.pdf
3. Compress tensioner spring SLOWLY using large water pump pliers and clamp.
4. Belt drops off.
5. Fit new belt. I used a toyota one. I attached picture of easiest method I found.
After I got it round the crank pulley I could tension the belt with both hands and there was a satisfying"snap" as it went over the edge of the tensioner pulley.
6. Remove tensioner "clamp" and double check with a torch that the belt is over all pulleys correctly.
Satisfying little job, knowing that you've got a fresh belt on that isn't going anywhere anytime soon.
Interesting approach to the tensioner!