To Increase the number of process
Step-1
Create pfile= /oracle/.... from spfile
Step 2
Shutdown database
Step-3
Amend that pfile and increase the number of processes
Step -4
startup the database with new pfile
startup pfile='/oracle/....'
Step-5
Create spfile from pfile='/otacle/....'
So that when you startup database next time it will read spfile (new)

Best of luck.
Regards