pfSense, vpn in tap mode and vlan mapping to resolve conflicting vlans between 2 sites

Hi! Perhaps you have an idea - I got 2 sites that need to be connected via VPN in tap mode. We have pfSense boxes for that. But the sites have conflicting VLANs. We're looking for a way to resolve this conflict using VLAN mapping. However, I'm not sure pfSense and it's openvpn implementation can do that. Any idea how to resolve this issue? Thanks :)