delete the intersection

=Increase the zoom level to see exactly the one node of the intersection
=Select that node
=Drag it a little bit to further inspect
=Click Edit => Undo to restore the original situation
=If it is the right node :
=Select that node once more
=Click Tools => UnGlue Ways
=You now have all the ways that connected at that intersection separate

=If you only want to remove just 1 way from the intersection :
=Select that way
=Slowly move the mouse pointer to the intersection node and if the node lits up :
=First press the Ctrl key (the mouse pointer will get a +sign) and than the left mouse button
=Now both the way and the intersection node are selected
=Click Tools => UnGlue Ways

If you change an intersection the ways nolonger connect. They nolonger route !
The bicycle-, walking-, and bus routerelations nolonger work are corrupted !

So be care full before you upload the Change Set to Osm
hth
Gys