Doubling this  amount  wouldnt  be  easy   ,  as OP asked  for  on how   to double  this  amount,  it would really  need   investment  though  in able to  double  it  but   this doesnt  mean that  you would able to double it safely because as we all know that  investment do have  risk  on  lossing   money.  You could actually  make some  huge  investments  like creating a gambling site or  an exchange site.