_content/doc: highlight 'remove old Go tree' step before extracting

Fixes golang/go#44426.

Change-Id: Ie7eb15c239e522d28412a4d8fe2db37bab55f4a4
Reviewed-on: https://go-review.googlesource.com/c/website/+/294369
Trust: Dmitri Shuralyov <dmitshur@golang.org>
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
diff --git a/_content/doc/install.html b/_content/doc/install.html
index d02d260..5055be0 100644
--- a/_content/doc/install.html
+++ b/_content/doc/install.html
@@ -79,19 +79,20 @@
     class="TabSection-tabPanel"
     aria-labelledby="linux"
   >
-    <p>
-      If you have a previous version of Go installed, be sure to
-      <a href="manage-install">remove it</a> before installing another.
-    </p>
     <ol>
       <li>
-        Download the archive and extract it into /usr/local, creating a Go tree
+        Extract the archive you downloaded into /usr/local, creating a Go tree
         in /usr/local/go.
         <p>
+          <strong>Important:</strong> This step will remove a previous
+          installation at /usr/local/go, if any, prior to extracting.
+          Please back up any data before proceeding.
+        </p>
+        <p>
           For example, run the following as root or through <code>sudo</code>:
         </p>
         <pre>
-tar -C /usr/local -xzf <span id="linux-filename">go1.14.3.linux-amd64.tar.gz</span>
+rm -rf /usr/local/go && tar -C /usr/local -xzf <span id="linux-filename">go1.14.3.linux-amd64.tar.gz</span>
 </pre
         >
       </li>