The short answer is no,there is no easy way to do this. Brain tanning is a complex and multi-step process completed over several days and involving the strictest attention to detail.Even a basic description of how to do it would fill several pages. I reccomend reading up on this forum or paleoplanet. I have tanned a few deer , an elk, otter, nutria, and i mostly use the "wet scrape method" as outlined in Matt Richard's book.
But, ok,ok, i will try to give a one paragraph description.
1. soak for several days in water
2. scrape off hair, and "membrane" (outer layer of the flesh side of the skin)
3. soak a couple days in a lye solution
4. scrape off epidermis- the upper layer of skin
5. soak in neutralising / acidifying solution 1 day
6. rescrape membrane + sew holes.
7. soak in brains, eggs or soap and oil
8. wring.
9. now the hard work starts- continually stretch and manipulate until dry- 4 to 8 hours..
10. sew into a bag shape
11 suspend over a fire of very rotten wood, forcing smoke inside the bag
12 turn bag inside out and smoke again
13 do the last 6 steps over again because it didn't come out as soft as you'd have liked.
well done braintan is so awesome that it's actually worth all the trouble, but it's easily as hard as making a good bow, and like bow making it never seems to come out perfect.