I think the official word is make the servo links 90degrees so make servo arm 90 degrees to servo, make control link 90 degrees to servo arm. Obviously 90 degree is a relative term since you are moving the control links to the arms in a diagonal way. I guess more like as close as possible to 90 deg.

The rest is just trial and error, if it shoots right lift the right servo up, left then left up, back then move rear up. I would take an initial measurement of the size of the links before and try to keep them somewhat close to what they are now when you move the arm in a ring.

I spent several hours at my LHS when I first got my blade, even factory it needed to be modified quite a bit.

Lastly it all comes down to feel.

DY