I'm aware of two ways but can't guarantee success.
1. Requires ADB. After making connection, type
adb shell mount -o rw,remount -t ext2 /dev/block/mmcblk0p5 /system
adb shell mv /etc/security/otacerts.zip /etc/security/otacerts.zip_DISABLED_OTA_UPDATES
2. Requires purchase of two apps. Good investment, even if you buy nothing else.
http://forum.xda-developers.com/showthread.php?t=946969
I went with method 2. Good luck..