Seems to me the 'easier' way is to buy a new dehumidifier that ALREADY has a hose attachment on it. :B
Buy a new small inexpensive one, they have the smaller reservoirs but it won't matter because it will have a drainage hose with the option of hooking up the 'included' hose for draining by passing the holding tank cup.
I put mine by the shower and run the hose to drain inside the shower.
I bought the de-humidifier on the advice of my RV repair guy to help assist my ac while staying in Florida for the summer. WHAT a difference in how much cooler it was in the RV.
Just saying I sure would NOT be drilling holes anywhere in my RV.