Replacing Input Shaft Seal

Hi everyone,

Just wondering if somone could enlighten me on how big/hard of a job it is to replace the input shaft oil seal.

My box seems to be leaking from under the shaft and would need an idea on how possible it is to change.

thanks

Box got to be split.
Main reason they leak is worn input bearings & to much shaft float so that needs to be addressed for a proper long term result. Quite a basic gearbox & not too hard to do but without experience or mechanical competence it will be a potential disaster.