  We provide the explicit combinatorial structure of the Kirillov-Reshetikhin
crystals B^{r,s} of type D_n(1), B_n(1), and A_{2n-1}(2). This is achieved by
constructing the crystal analogue sigma of the automorphism of the D_n(1)
(resp. B_n(1) or A_{2n-1}(2)) Dynkin diagram that interchanges the 0 and 1
node. The involution sigma is defined in terms of new plus-minus diagrams that
govern the D_n to D_{n-1} (resp. B_n to B_{n-1}, or C_n to C_{n-1}) branching.
It is also shown that the crystal B^{r,s} is perfect. These crystals have been
implemented in MuPAD-Combinat; the implementation is discussed in terms of many
examples.
