Elder is earned by attacking in friendly challenges with a war army and showing us that you know how to attack. It is a requirement to become Elder to stay in the clan so you must know how to attack well. Those that try and stall, or duck doing these challenges will be kicked.
The simple answer is - you probably can't. This is a position of extreme trust and is reserved for long time, and mature members.
Co-leaders help run the clan, its not about status to us - so if status is that important to you... you should probably find another clan... or start your own.