- when time comes there will apear a buton at the bottom of the garage window called "SPECIAL BATTLES" u need to click that buton
here u can see in the pic the butonSpoiler
- then u have open the "SPECIAL BATTLES" window and will include any special battles u have in that time. (u can see en the first screenshot i have the IGN Tournament and a Clan Wars battle, both in the same "SPECIAL BATTLES" window
- then you need to click on the battle u want to join, and that will open other window (Second Screen)Spoiler
- there u chose the tank, ready up and move you from the "reserve team" to the "regular team"
then you just need to wait to the countdown to end and you will be at the fight
i hope this help
PS: anyone that want to use this screenshots with better english than mine (my english language skills are bad , sorry) feel free to use them