Hi Rizwan,
a. u need to send the mail to licensing@cisco.com along with PAK code and serial number of 2951 router.this u can get by running command show version or show license udi
b. after u recive the license file[uck9_license.lic], upload this file in router flash using command copy tftp flash:
c. u can check the same by running command show flash:
d. now u need to install the license file . run the command license install flash:uck9_license.lic
e. now run the command license boot module c2900 technology-package uck9 and accept :yes
f. reboot the router
g. after the router reboots, run command show license feature /sh license all.
regds,
aman