You can go through the side or the bottom of the spa. You'll need a new bleedline fitting(which glues into the compartment wall), a length of the 1/4" hose, a few 1/4" clamps, a 1/4" barbed coupling, some new spray foam, and the "exact size" drill bit to drill out the old bleedline fitting. Consult your local HotSpring dealer, preferably one of their techs, or we can send you what you need. If responding to my store use the following email,
scarritt@snet.net and copy and paste what I just wrote you.
The best glue to use is TRANSITIONAL GLUE-ABS TO PVC.