Ok mate
The spring is attached to the bracket at the top by 2 nuts and allen bolts (not the bearing bolt )you can tell the difference by using a 10mm spanner (it won't fit the bearing bolt as that is 13mm)
Loosen those two
The spring is attached in the middle by 2 nuts and allen bolts (again they are 10mm)
Loosen these two as well
The spring will now be able to rock side to side
Look along the underneath of the footplate from the front and you can see the spring
Check the position of this on the good one and then set the other one the same but opposite
Eg If the good stilt spring looks like it is a bit to the left put the other one a bit to the right
Tighten all up and they should be ok
If this doesn't work have a look at the fixing bracket under the footplate as that can come loose sometimes
If all the above fails post some pics so we can see what the problem is
Jason