The cache name says it all. Be confident that you can descend as well as ascend. The tree (it's a very large oak) is just off the minor roadway and is hidden in full site. The best way to see it is to stand on the little roadway (but not whilst one of the very occasional cars is coming by!), probably about 10 metres before the tree (if you were coming from the M50 bridge) and look up in middle of the tree, where all the big branches start to split out, and look a little higher. I did not use any special equipment to set this cache, but you may choose to use some, including ropes for safety. It's a relatively straightforward climb, hence it's only a T4.
Please play fair to the spirit of this cache and only log it if you climbed the tree all the way to the cache.