Oil leak on the rotor timing out put shaft
If you mean the camshaft seal, yes, you would need to pull the timing belt and sprocket off, and if you are anywhere near the service interval for the belt, replace it and the water pump (unless the water pump is very easy to service, and the tensioner.
You will probably need a (gear/sprocket) puller to get the sprocket off and a another type of (seal) puller to get the seal out. You could probably extract the old seal with a screwdriver, but it's not recommended. Get a Haynes manual (around $20) before you even contemplate doing this youself. If you haven't done this before, are mechanically inclined. and have all the tools, you will spend about 1/2 a day to do either the cam seal by itself, or the seal, timing belt, tensioner and water pump. Once you have it all apart, the last three components will only add an hour to the job, and you won't be stranded when the timing belt breaks.