Getting it setup is the hardest part, I did do a write few years ago, it might have been on the old forum, You put 4 axles stands out, it's probably better using knicker elastic than string, you then need to measure from the end of the stub axle to the elastic/string so you get the same both sides, but you have to have the two axle stands at front & back the same width apart. Then you can measure from front of rim to string & rear of rim to string, then using your good friend Mr Trigonometry you get the angle. But leave yourself several hours as each time you change anything you have to check everything again.