what do I need to do to make my wife join the lifestyle? She is very conservative.
Oooh, no, wrong wording and you really won't get far with that type of thinking, sorry. No, none of us can "make" our wives do anything. In fact most of the time it's the women who are in charge in the lifestyle.
If you are really interested what you can and should do is begin communicating openly and honestly. This whole lifestyle is based on a couple of adults who care about each other being honest enough with each other to admit that while they care about each other, they do want variety and excitement in their sex lives. The communication has to be honest enough and with enough trust that it is not threatening and instead for most couples I know it brings them closer together by sharing.
Then you can talk about rules and boundaries that allow for some adventure and excitement but still allow for trust and security. Most of us started conservative and as our confidence grew we adjusted our rules.
Yes, I know it sounds all touchy-feely, but as you learn to tell each other what you really want it gets better.