Hi, novice diy'er/gardner here.

I want to transform my South London back yard into a rural idyll.
Currently my back yard is almost completely covered in concrete, with an
extra thick bit where a ludicruously oversized shed sits (that's going
too). I guess I want to remove this, but how do I go about it? How thick
is it likely to be? Do I need to hire a pneumatic drill or similar?

When I remove it, will I likely just have soil underneath?

Another consideration is that manhole covers and drains are built into
the concrete.

Thanks,
Dan