Hello again
Another method is once you have tightened the long bolt using the Phillips screw driver . then screw the nut on with a lock washer as far as it will go finger tight and then use a pair of vise grips on the end of the thread to hold it from turning while you tighten the nut .
both ways will work . And if the Phillips head has stripped then take it out and use a Rotary tool with a cut off wheel to grind a slot so you can then use a flat screw driver on it .
Truly hyflyer9 Daniel.