How do I take over an inactive fanclub?

Ты can't "take over" a club. клубы aren't owned by the person who started them - they're owned by every member. However, Ты can still get the Иконка and banner changed. The method is different depending on whether the club has 10 или еще members.

The first thing you'd need to do is start a Форум thread in the club asking people to suggest new Иконки and banners. Leave that running for about a месяц или two. Then,if the club has less than 10 members, Ты make 2 Опросы asking members to vote on their favourite Иконки and banners, then message one of the F4 asking them to change the club's appearance to the winners. If the club has еще members, Ты need to use the buttons on the вверх right of the club's main page which say "suggest a new banner/icon". These make Опросы which cost members 5 golds to vote (to discourage uninterested people from spam-voting) and the Иконка and banner get automatically changed to whichever win these polls.