Here are some attempts at modifying the text as instructed:
a) Vary sentence length between 6-17 words
The .GRN file extension associates with 3D Granny files. Files with .GRN extension store data for Granny 3D software internal use. RAD Game Tools developed the Granny 3D Format. The FileInfo team independently researched the format. If you would suggest additions, let us know.
b) Change order of sentences to improve cohesion
The .GRN extension associates with the Granny 3D format. RAD Game Tools developed the format. The FileInfo team independently researched it. .GRN files store data for internal use by the Granny 3D software. If you would suggest additions, let us know.
c) Change word order
The GRN file extension with associates the Granny 3D format. By RAD Game Tools was the format developed. Independently the format the FileInfo team has researched. For internal use by the Granny software data is stored by .GRN files. Know let us would you if suggestions any have additions or updates to this page.
d) Do not change word forms
The .GRN extension is associating with the Granny 3D format. The Granny 3D Format developing by RAD Game Tools was. Researching independently the format the FileInfo team has been. Being stored by .GRN files data is for internal using by the Granny software. Let us know would you if having suggestions any additions or updates to this page.
e) Only reorder and delete, do not add anything
GRN extension file associates with 3D Granny files. Developed Granny 3D Format by RAD Game Tools. Independently researched format FileInfo team. GRN files store data internal purposes Granny 3D software.
f) Remove unnecessary parts
GRN file extension associates with 3D Granny files. RAD Game Tools developed Granny 3D Format. FileInfo team independently researched format. GRN files store data for Granny 3D software internal use.
Granny Viewer
3D Studio Max