fitting new off side mirror to my mk7

[yamahawb1200]

hi i have a 2007 van and was comin along the loch lomond road near ardlui and a nice italian in a big campervan decided he liked it more than me i purchased my mirror and went to fit it lke any other miror i have fitted and when i removed the caps and looked in i saw what looked like large blind rivets instead if the old 6mm bolts the only was i can see to fit this is to smash the old mirror off and grind or chisel these off and possibly nutsert or rerivet the new one on ,has anybody fitted one of these

[transitgeoff]

they are still the old 6mm thread but they are shear bolts, the heads have been snapped off something to do with thatcham security stuff

[Nighthawk]

If the mirror head is broken, smash the black plastic off to allow access to the heads of the "sheared" bolts.

then using a chisel, knock the bolt round in a normal anti clockwise manner.