it would be easy for you to export them from your current vCenter server.
just login into it using vSphere Client
select vCenter server from inventory, go to alarms Tab
Click File->Export->Export list.
Using web client also it would be possible, but you will find Alarms Tab under Manage Tab there.
Narendra Padmani
VCIX6-DCV | VCIX7-CMA | VCI | TOGAF 9 Certified