There is an easier way, which is also more efficient. The internal outhaul is a poor design in the first place for a couple of reasons one of which is the alum slug slug that rides in the bolt rope slot. If you look closely at it you'll see the pulling motion is downward, which causes the slug to dig into the boom thus greatly increasing the friction making it difficult to pull aft.
My solution was to install 2 small Harken triple blocks, which are expensive little buggers but they work great. One is attached to the clew cringle and the other to the topping lift tang at the end of the boom. The mechanical advantage is very good. I could probably pull the cringle out if I wanted to. The new outhaul line goes into a small turning block and then goes up to a cleat about where the original line exits the mast. You could probably use the existing jamb cleat but i did not want to mess with it.
The outhaul is one of the most important sail trim controls for the mainsail and sadly most are frozen in some position due to the crappy internal system. What happens is the frozen setting is right for one point of sail and wind condition and wrong for all others.
There is a better way than my mod and that is to add a small track and car system but that involves cutting the sail at the clew. It would work great in a loose footed application.