how easy is it to upgrade to joomla 2.5 - Joomla! Forum - community, help and support

i have joomla 1.5 , have joomla 1.5 template template club , couple of compents , modules joomla 1.5. wondering how hard upgrade joomla 2.5

hello,
if have knowledge in html css, wont have problems upgrade template. can see article :
http://docs.joomla.org/upgrading_a_joom ... joomla_2.5

to migrate joomla!, depend of extensions installed on website, have equivalent on joomla 2.5 ?
to migration (on local computer example), can read :
http://docs.joomla.org/migrating_from_j ... joomla_2.5

but before backup website. twice