changing the vt of a nmos model

[Ausaaf Khan]

How do I change the threshold volatge (Vt) of a NMOS device if I have
a model file for the nmos. Below are the parameters in this file, I
changed the VTH0 parameter but did not see any noticeable changes in
my spice run. Do I need to change any other parameter?

..MODEL tsmc20NHV nmos ( LEVEL = 49
+VERSION = 3.1 TNOM = 27 TOX = 4.1E-9
+XJ = 1E-7 NCH = 2.3549E17 VTH0 = 0.4000000
+K1 = 0.5915709 K2 = 2.432705E-3 K3 = 1E-3
+K3B = 2.881708 W0 = 1E-7 NLX =
1.556472E-7
+DVT0W = 0 DVT1W = 0 DVT2W = 0
+DVT0 = 1.8671789 DVT1 = 0.5070952 DVT2 =
-0.0135063
+U0 = 275.5555875 UA = -1.150238E-9 UB =
2.014145E-18
+UC = 4.217107E-11 VSAT = 1.002265E5 A0 = 1.900204
+AGS = 0.4125379 B0 = -1.06835E-8 B1 = -1E-7
+KETA = 2.505893E-4 A1 = 4.377095E-4 A2 = 0.9584318
+RDSW = 105 PRWG = 0.5 PRWB = -0.2
+WR = 1 WINT = 9.458635E-9 LINT =
1.257015E-8
+XL = -2E-8 XW = -1E-8 DWG =
-1.204617E-9
+DWB = 9.664221E-9 VOFF = -0.0946268 NFACTOR = 2.3761356
+CIT = 0 CDSC = 2.4E-4 CDSCD = 0
+CDSCB = 0 ETA0 = 1.375861E-3 ETAB =
1.376595E-4
+DSUB = 2.75603E-3 PCLM = 0.8650201 PDIBLC1 = 0.2388154
+PDIBLC2 = 3.957307E-3 PDIBLCB = -0.1 DROUT = 0.7285083
+PSCBE1 = 6.140394E10 PSCBE2 = 5.822994E-8 PVAG = 0.1710916
+DELTA = 0.01 RSH = 6.7 MOBMOD = 1
+PRT = 0 UTE = -1.5 KT1 = -0.11
+KT1L = 0 KT2 = 0.022 UA1 = 4.31E-9
+UB1 = -7.61E-18 UC1 = -5.6E-11 AT = 3.3E4
+WL = 0 WLN = 1 WW = 0
+WWN = 1 WWL = 0 LL = 0
+LLN = 1 LW = 0 LWN = 1
+LWL = 0 CAPMOD = 2 XPART = 0.5
+CGDO = 7.32E-10 CGSO = 7.32E-10 CGBO = 1E-12
+CJ = 9.775464E-4 PB = 0.7224132 MJ = 0.3611113
+CJSW = 2.244809E-10 PBSW = 0.7522727 MJSW = 0.1
+CJSWG = 3.3E-10 PBSWG = 0.7522727 MJSWG = 0.1
+CF = 0 PVTH0 = -1.4684E-3 PRDSW =
-0.6888789
+PK2 = 8.530602E-4 WKETA = 1.029979E-3 LKETA =
-9.473178E-3
+PU0 = -0.2034778 PUA = -2.37215E-11 PUB =
4.74506E-25
+PVSAT = 901.6731904 PETA0 = 1E-4 PKETA =
1.329782E-3 )