You may not need a bypass pulley, you may be able to just buy the belt for a 2005 Sedona without A/C. But you'd want to study the belt routing diagrams of each to determine if it's that simple.
You can't legally drain the refrigerant and recharge, even though you can purchase replacement refrigerant and the tools to evacuate and recharge. Your best bet would be to go to a shop you trust that has the equipment to recover the refrigerant from your A/C system. Explain to them that you will be replacing the compressor and you will bring the vehicle back to them to have the system evacuated and recharged. Ask them if they'll credit you for the amount of refrigerant they recovered from your system when you have them recharge it.
-Rod