http://www.1999.co.jp/eng/plamo/index_e.asp?Bno=&Typ1_c=102
This site has instructions for various model kits. The Merkava instructions are on the fourth page of the 1/35 Tank category. The site is worth bookmarking since you can also use the directions as a guide when ordering sprues from Tamiya America.
Here is a direct link to the Merkava: http://www.1999.co.jp/asp/GoodsDetails_e.asp?Bno=&Typ1_c=102&Typ2_c=103&Typ3_c=616&SPage=4&SC=77&SN=Military+1%2F35+%28Tanks%29&It_c=10000219&andor=0&scope=0&scope2=0&thumb=1&sortID=1&urikire=1&sort_sort=0&ItKey=&app_url=shop_right_e.asp