I wont be posting instructions, In stead ive just posted these for you to try and build from.
If you want original size pictures, click a picture (small one), click the picture again (bigger one), then at the bottom of the screen look for (original file) click the link next to it, save image or build from that.

Pros:
RBG / Sling shot
Barrel is removable
Comfy handle

Cons:
Floppy stock (but reliable)
No scope

The Body
Pic 1: Stock
Pic 2: Handle + Stock Attachment
Pic 3: Trigger Guard + Body
Pic 4: Body
Pic 5: Body
Pic 6: Body + Small Rail For Bi-Pod
Pic 7: Overview
Pic 8: Top View - Stock
Pic 9: Top View - Handle + Stock Attachment + Trigger Guard + Body
Pic 10: Top View - Body + Small Rail For Bi-Pod
Pic 11: Inner Handle + Stock Attachment
Pic 12: Inner Stock
Pic 13: Under Trigger Guard + Body

The Barrel
Pic 14: Trigger + Body
Pic 15: Barrel
Pic 16: Barrel
Pic 17: Barrel + Rubber Band Attachment (2 Y Connectors)
Pic 18: Barrel
Pic 19: Barrel (Change The Green To A Purple For The RBG)
Pic 20: Overview
Pic 21: Top View - Trigger + Safety

Putting The Barrel In The Body
Pic 22: Y Connector Holds It In Place
Pic 23: Y Connector Holds It In Place
Pic 24: Cut Ends
Pic 25: Insert So It Wont Fall Out Whilst Your Pulling The Rubber Band Back
Pic 26: Insert So It Wont Fall Out Whilst Your Pulling The Rubber Band Back
Pic 27: Locked, Loaded, But The Safety's In?

Videos
How The Barrel Comes Out - http://www.instructables.com/file/F8VL8JMG1QVZ6F8/
Test Fire 1, From 4 Meters - http://www.instructables.com/file/FRJB6EOG1QWB4H6/
Test Fire 2, From 5 Meters - http://www.instructables.com/file/FQHY7NXG1QVZ6V4/