Just use CE and attach it to the iw5mp_server.exe
Add the address 0x6DA708 and type as Float
Edit the value. Voila :P
P.S. You also need to add the following: (Due to falling damage if jumpheight is set too high)
0x6D9634 [FLOAT] - Minimum height for damage. (I use 999999)
0x6DE490 [FLOAT] - Max height (Here I use 1000000)