I suspect that this may be a "how long is a piece of string" type of
question, but thought I would seek the advice and knowledge of the
group.

We've just had the structural engineer round and the good news is that
I don't have subsidence. The bad news is that the two joists that run
directly underneath the back are rotten as hell. These joists run
between the two external walls at either side of the bathroom and one
of them butts up pretty close to the rear wall of the property. Access
to them from beneath is pretty easy as theirs currently no ceiling in
the kitchen beneath them.

So, the question is, how hard a job is it likely to be for me to remove
these two joists and replace them with new timber. Is it in the realms
of DIY, or is it really a job for the professionals? I class myself as
being fairly competent and unlikely to cut corners or do a bad job but
still...

As always, thanks for any and all advice.

Seri