Switch off for hole to stairs

[sune73]

Hi Forum,

I need advice on the "avväxlingen" to make a hole in the intermediate floor for the stairs.
The horizontal beam needs to be removed, how to do it?

See images

Regards

 

[Västerhaninge 17]

Why not shift support to the rafters' lower arms or a load-bearing interior wall. The heavy post on the right side can be moved to the right (which also needs to be shifted above).