Need Help With Exhaust System!!!

Have a Honda Accord 1988 LXI M/T F/I 2.0L.
Have to replace the whole exhaust system
from the Header to the muffler. I have a
universal catalytic converterer. Do I
have to weld it on? I cant screw it on
or I would. What do I do? PLEASE HELP!!!!

you can clamp it on instead of welding it