sjoerd@ae1-server:~$ sudo aptitude purge apache2
Reading package lists... Done
Building dependency tree... Done
Reading extended state information
Initializing package states... Done
Building tag database... Done
The following packages will be automatically REMOVED:
  apache2{p}
The following packages have been kept back:
  linux-image-amd64-server
The following packages will be REMOVED:
  apache2{p}
0 packages upgraded, 0 newly installed, 1 to remove and 1 not upgraded.
Need to get 0B of archives. After unpacking 81.9kB will be freed.
Do you want to continue? [Y/n/?] y
Writing extended state information... Done
(Reading database ... 15536 files and directories currently installed.)
Removing apache2 ...
sjoerd@ae1-server:~$ sudo apt-get install apache2-common
Reading package lists... Done
Building dependency tree... Done
apache2-common is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 1 not upgraded.