Have you tried introducing them on neutral territory? I've heard that is usually a good place to start...
Also, give something REALLY good to Remy whenever the Boxer is around. It helps him associate the Boxer with really good things (like an extra special treat Remy really likes).
A gradual adjustment sometimes works too. Try leaving a blanket or something to absorb their scents and then switch them and put the other dog smelling blanket in their favorite spots. This gets them used to the smell... then you work up to face to face contact in baby steps.
Hopefully someone else has some things you can try, but this might be a place to start. Good luck!
Edit: YAY my 500th post!
