To install and tension the blade guard spring, you have to remove the upper stationary blade guard from the saw housing, then remove the 3 screws behind the blade guard that hold the blade guard bearing and bearing housing, which will allow you to remove the blade guard and blade guard bearing as one piece. The screws are accessed through the the 2 holes on the interior side of the blade guard.
To reinstall it, install the spring into the saw housing so that the tab on the spring goes into one of the holes within the shaft/bearing housing of the saw housing. Once this is in place, push the other tab on the other side of the spring into a small hole on the bearing housing of the blade guard. Once you get the spring installed, partially push the blade guard bearing housing into the saw housing and then 'wind' the spring by rotating the blade guard to bring tension on the spring. Once it is to the tension you desire, push the bearing housing all the way into the saw, reinstall the 3 screws and reinstall the upper blade guard.
