際に/際/際は => occasion, time N2
[際「さい」]して/に([際「さい」]し)/に[際「さい」]しての => At the time of A (which starts now).. N2
Time, Situation
に代わって => instead of; replacing; on behalf of ~ N3
に際して => on the occasion of; at the time of ~ N2
代わりに => instead of; as a substitute for​; in exchange for; in return for N3
[代「か」]わり => Not A, but B, B in place of A, Instead of A, B; In exchange for A, B N3
Comparison, Exchange