This is a bearing wall that supports the second floor and roof and is
near to the corner of the second floor dormer.


A load Bearing wall? and you are asking at an Internet Newsgroup?

Where I live, and this depends on your local government, if you touch a
load bearing wall, you need a building permit. Period. The kind of B.P.
where the building inspector wants to review your plans and see your
calculations on the load. (and how you are going to proceed in steps so
the load is temp supported during construction.) As in load and
distribution of the weight to the foundation.

I think I am going to mark this thread. Could be good reading.

Personally, If it was my home, I would see if I could get a quote for how
much it would cost to get a professional (architect or P. Engineer) to do
the math and your building structure then come up with a plan that will
get a building inspector's OK. But your home, your money, go with what
every plan you decide to do.