Many new avatars on Opensim wonder how they can get their second life inventory over to another grid. 
These tutorials show you how to do just that.  The video description mentions the links to fetch the right (free) tools for the job.

1. How to export your Second Life avatar and inventory to an OpenSim grid

https://youtu.be/oqnMLKAN6tY

2. How to export rigged mesh

https://youtu.be/Y4rU4Xwx-W4