Summoning My Old LG Optimus L3

My mother has been using this LG Optimus L3 for about 2 years. By the time this post written, it's obsolete, especially the storage was unacceptable, only few hundreds MB's available for systems app and other installation, and the other 1 GB storage was partitioned as secondary.

I bought her a new phone to replace her old LG, and she look happy :)

And i decided to keep the LG as my secondary phone.
So, after googling, reading, testing and comparing for some amount of time, i manage to root it and found the best solution for the storage issue.