if its oil filter tis easy, just get a new one and fit it just make sure you smeer the new rubber seal with fresh wngine oil before you fit, have you had an oil change etc done recently??
ibe had a rubber seal fail on me before on an oil filter, changed the oil+filter the day before, went to work, on the way home the oil light came on... the seal had split... and pumped the contents of the sump onto the orad, luckily id iddnt seize it up........
hope its a simple fix for you.... oil leaks are a pain in the ass, one drp spreads like wild fire and can be hard to trace.....
dose sound like your filter seal though ....
