Step 1 :  choose bigger number  : 1188 > 504
On dividing $1188$ by $504,$ we get
Quotient = 2 and remainder  = 180
$\Rightarrow 1188=504\times 2+180$

Step 2: on dividing 504 by 180

Quotient = 2 and remainder = 144
$\Rightarrow ,504=180\times 2+144$

Step 3 : on dividing 180 by 144
quotient = 1 and remainder = 36
$\Rightarrow 180=144\times 1+36$

Step 4 :  On dividing 144 by 36
quotient = 4 and remainder =0 
$\Rightarrow 144=36\times 4+0$
Since remainder is zero, stop the process