This is what you need to do:
1) copy the .TAR from RSP1 to RSP0 this is how you do that:
copy harddisk:ASR9K-iosxr-px-K9-5.3.3.tar location 0/rsp1/cpu0 harddisk: loc 0/rsp0/cpu0
2) Once the .TAR is on RSP0 (or active RSP) this is how you install it:
admin install add harddisk:/ASR9K-iosxr-px-K9-5.3.3.tar
Pay attention to the forward slash after harddisk:/
install add harddisk:/
Regards
Eddie.