hey people!!

so my band wants to cover Cemetery Gates from pantera and i have a problem with reaching certain notes Phil sings

no, people i am not plannig on doing the GAAATES!! screaming thing...

actually im having trouble on the heavy part after the clean verses

what can i do?
You can try to falsetto it. Depending on how soon you have to perform you can try training those notes. Find it on a piano and try warming up by doing scales up to that notes.
This is a pretty good exersise too.

If you do these things every day high notes should become easier. I knew a guy who extened his range from G4 to Eb5 over a few years by doing this.

Also for the GAAATES!!! thing you can just do a vocal fry type thing and fake it.

Bruce Dickenson does it here.
thanks man thats just the tips i needed im gonna start practicing the scales,

we are doing the song next month so i will go with the fry thing also thanks for putting that song as an example we are also going to play Aces High!
I dunno, practice it until you can? The voice is like a muscle, it'll improve the more you use it. I never used to be able to hit higher notes until I started singing along with literally everything I knew the words to. Eventually, it just came to me. There are obviously vocal exercises you can do to improve your voice, but I don't know any of them.
Q: Favourite Pink Floyd song?
A: The one where they get wicked high and play Emin and A for an hour.
In general, good technique expands your range. Yes, practice matters, but taking some lessons to get your fundamentals sorted out with undoubtably improve your range. WIll it improve it enough? I dunno.