Just remove the WAVECAR file and start from scratch, no parameters must be specified in the INCAR file. The defaults for some parameters will be:
ISTART = 0 # startjob: no WAVECAR file ICHARG = 2 # charge: from atoms INIWAV = 1 # random initialization for wf. NELM = 40 # maximum of 40 electronic steps NELMIN = 2 # minimum of two steps NELMDL = -5 # no update of charge for 3 steps EDIFF = 10E-4 # accuracy for electronic minimization