It looks like my gear change shaft is damaged that I can't see I have another engine Can I remove the shaft without stripping the engine hopefully I can remove the cover that holds the oil seal and remove the shaft
Have a look at Section 8 of the manual https://www.2fiftycc.com/index.php?resources/vt250-spada-workshop-manual.62/
Does the shaft look bent? Otherwise, if you're careful, the oil seal around gear change shaft can be removed by drilling a small pilot hole then inserting self tapping screws a few turns. Once they're in use them to lever the leaking seal out. A new seal can then be fitted using a socket or piece of pipe or plastic conduit [anything suitable basically] to push the new seal into place.