Samsung Galaxy S 2 Plus (GT-I9105P) Firmware Overview
What is the latest GT-I9105P firmware?
I9105PXXUBOB2, released May 29, 2015 for region NEE with Android 4.2.2. The archive holds 2 official builds for this region.
Is the Samsung Galaxy S 2 Plus still getting updates?
Most likely not: there has been no new firmware since May 2015, so Android 4.2.2 is the last version this model got. The final builds below are still the best choice for a clean reinstall.
GT-I9105P firmware for region NEE
How to Flash GT-I9105P Firmware
Put the Samsung Galaxy S 2 Plus into Download Mode, load the BL, AP, CP and CSC files into Odin on a Windows PC and press Start. Use HOME_CSC to keep your data, CSC for a full wipe.