Cowboys, vaqueros (Mexican cowboys) and even cowgirls are known to wear chaps to protect their legs from brush while riding horses. Chaps consist of two separate trousers connected at the waist but only cover the legs. Since chaps are similar to trousers in design, creating chaps is not as hard as you might think. You can alter a pair of trousers such as blue jeans or leather trousers to create chaps.
Lay your trousers on a flat surface with the front side up.
Trace a "U" shape starting at the crotch of the trousers using a black colouring pencil. If the trousers have pockets, do not draw beyond the pocket section. Draw a curved line on one side of the crotch section to the waistband. Then draw another curved line from the crotch to the waistband.
Turn the trousers over and draw a pattern for the rear section. Draw a curved line from the seam on the bottom butt area to around the pocket section. Continue to the waistband on both sides of the rear section. The rear part will be totally removed.
Cut the pattern that you just drew for the front and rear sections.
Turn the trousers inside out. Sew by machine the outer edges that you just cut to create a seam.
Try the chaps on over your current pair of trousers to see the fit.