Here is how I made a few simple changes to the original Alternative Claw on Thingiverse so I could form a pad of Sugru on the grip.
Submitted by Mobile Makerspace for the Instructables Sponsorship Program
Step 1: Download
Download the original STL file from Thingiverse
Step 2: New Tinkercad Account
Step 3: Tinkercad Import
Step 4: Tinkercad Edit Hole 1
Step 5: Tinkercad Edit Hole 2
Step 6: Tinkercad Edit Complete
Step 7: Export From Tinkercad
Click Design >> Download for 3D Printing >> Then choose STL.
Download the STL file to your computer where you can find it.
Step 8: Upload to Thingiverse
To make it easy on myself, I go to the original object and select remix it, located on the right side.
Simply drag your new STL file into the area that Thingiverse provides you, fill out the details of the project such as the description, and a title, then hit publish!
Done!!! - One more Thingiverse item enhanced and ready for Sugru!