To use the first option, you'll have to create a local traffic policy (Local Traffic -> Policies -> Policies List, then click 'Create' at the top right).
You'll need to create two rules within the policy. The first rule will be your default rule. No match condition, but your action should be asm request enable and specify the ASM policy you want to use (/Common/MY_ASM__POLICY_NAME). The second rule will be for your application that you want to disable ASM on. Your match condition will be http-uri request path contains "uri-of-application", and your action will be asm request disable.
After these two rules have been created, move your default rule (enabling ASM) to the top of the list.