NAT'ing and IP - help needed

Wonder if you guys can help. I have configured a site to site vpn (tunnel works and is connected).

However I am told that the other end will only accept traffic originating from 10.2.1.8/29.

Our local network is on 192.168.40.0/24

I'm told to NAT 10.2.1.9/29 to my PC. How do I go about setting this up this NAT rule?

Thanks in advance