Hey Andrii,
Pleaes see:
http://www.spi-electronics.nl/
On this page I can do what I want but I cant remove ore replace the current sidebar.
This is the text of the sidebar I don’t want….:
No Widgets Here Yet!
You see this text because you
haven’t placed any widgets in
the sidebar widget area! Please
go to your website’s admin
panel ‘Appearance’ – ‘Widgets’
and place at least one widget
into the sidebar widget area.
And yes I have done what this texst is asking me, on other themes I now how it works.