Thought i killed my olive tree

hello all as title says in my amateur wisdom i brought my new olive tree into the conservatory last year and i think the extreme hot and cold got to it and the whole of the ball top just dried up and went brittle and brown...kind lady in garden centre told me to test under the bark and to cut it right back... it is actualy shooting again but further down the tree almost from the bottom...now there is a very obvious change in the colour of the tree as a sort of bark with green look up untill about a foot from the top when it goes brown.... should i cut the top off at this point if so how do i do it and do i need to seal the open wound so to speak.... i could just buy another but we got this with some money off our wedding last year and realy want o save it if possible
any help would be good
regards
john:dh:

 

I think if you are certain any part of the plant is dead its OK to cut it back to live growth.

A fine toothed saw would be ok in the thicker parts, a pair of secateurs, on most of it.

I dont think wound sealing is recommended these days, nature will heal any cuts.

It will probably grow in bush form now, unless you want to get involved in some serious pruning and training.