Nope you do not. All you need to do is get a breaker bar/large torque wrench down to the belt tensioner to pivot it counter clock-wise. There should be plenty of room for this both above and below the engine. I know for sure its easy to access from below. If you do need to end up taking it off its easy as hell so it shouldn't be much of a hassle. Why do you need to remove the belt? Is it worn?
If you are having a hard time visualizing this let me know I can post pictures. I'm pretty sure our pulley setups should be the same but they could be different. I have an 03.
KB 2.1L | Stock F. Pump + KB BAP | KB CAI w/ 90mm MAF
MAC O/R H 2.5" | Flowmaster 44 CB 2.5"
Tokico D-Specs | MM FLSCFs | J&M S/S LCAs | UPR S/S UCAs
Nitto NT05 315/35/17 | FR 3.73s
Totalled 1/25/2013 | Rebuild/Full Paint Completed 6/15/2013
Mustang's 50th Anniversary Charlotte, NC 4/16/2014-4/20/2014