imported post
PutWD 40 on the three bolts on each tip and leave overnight , then get an 8 mm spanner and very slowly work them loose . as you loosen them a little then tighten them up again and this is the only way you will get the bolts out without breaking them ,They are very fragile ,, take the 3 bolts out and then work the tip loose by lifting it up and down and side to side ,it will come off and then refit your new ones .all you need is a bit of patience ,Ciaran