YBR250guy

Hi All How hard is it to replace the side engine cases on a YBR250. There are two nearly new ones on ebay at the moment http://www.ebay.co.uk/itm/YBR250-Yamaha-righthand-crank-case-cover-/151219391109?pt=UK_Motorcycle_Parts_13&hash=item233560ca85 mine are pretty crap and for a few quid (hopefully) and new gaskets I could get my YBR engine looking like the paint hasn't fallen off. Is it simply taking care, noting were all the bolts go and refitting everything, or is in much more involved and I need special tools. Any help appreciated. Cheers YBR250guy