quickstart.rst: If the following instructions don't Just Work...

[Zooko Wilcox-O'Hearn]

Hello Nigel!

Welcome.

> How do I replace the older system installation with the later one 'built'
> from the download directory?

This is really a question about how you wish to maintain your system.
There are lots of ways you could do this.

One option that you might like — judging from the fact that you used
Debian to install the v1.10.0 one — is to use Debian to upgrade it to
v1.10.1. The latter is now in Debian, thanks to Ramki Muthukrishnan:

https://packages.debian.org/sid/tahoe-lafs

What *I* do on my system is I remove the Debian version from /usr/bin,
and then I do *not* install the new version into /usr/bin nor
/usr/local/bin, but instead I edit my PATH to point to the local
directory where I have the new version built.

Hope this helps! If not, go ahead and ask for more. ;-)

Regards,

Zooko