Removing bolts from engine mounts

Hi Lads and Lassies,
I recently bought a set of Hepco and Becker tank protection bars for my 2014 Tiger 800XC. In order to fit them, the two front top engine mounting bolts have to be removed. Does anyone out there have tips on how to remove the mounting bolts as they are proving to be stubborn and the nuts difficult to reach in their very inaccessible position? If anyone can help please also let me know what size of socket is required for the nuts as my old eyes are struggling to see them clearly in their dark recesses.

Cheers...