Email service BC in the town your going to hunt...the customer service rep with forward everything you need to fill out before hand, email it back with a copy of your drivers License. Then just show up and pay. I just went through this for my turkey hunt...took a few emails and that's it. My lic is waiting for me to pick up Thursday for my Turkey hunt that I applied for Yesterday.
If your going after big game it takes a min 30 days to process and you can do it through ministry of environment in Victoria, send them payment and they will send the license to your Alberta address. Your host will have to have an active bc hunter number and license and will have had to purchase a big game tag in the last two years to be eligible to host you.
Fyi I am a former BC resident who has hosted many Albertan buddies in the past. I now live in AB and surrendered my BC hunter number when I moved so I get bent over by the BC government every time I want to hunt my Families land.