When you install the VPN client you are given three choices:
- Endpoint Security VPN (requires an Access license or one of the SandBlast Agent ones)
- Check Point Mobile (requires either a Mobile Access license or licenses per above)
- SecuRemote (requires no license, but has significant restrictions)
I recently wrote up something on how to configure your gateway to support SecuRemote.
It also covers how to configure IP Pool NAT.
However, if you're talking only five users, depending on your license, you may already be covered.
Most modern licenses include Mobile Access for five concurrent users.
In which case, you can use Check Point Mobile and configure Office Mode.
R77.30 is VERY much End of Support at this point and I highly recommend upgrading to R80.40.