alesis monitor issuessssss

[casual-p]

hello all, tried searching for this but didnt come up with anything. a while back whilst alesis were reconing my m1 active 620, they decided to damage my tweeter and send it back to me broken. because i don't want to pay a further 30 quid on sending the monitor back to them, ive opted for them to send me a replacement tweeter so i can fit it myself. but i havent got a clue how to remove the "acoustic waveguide". its basically the grey bit that surrounds the tweeter that sits flush with the cabinet - i guess its clipped in somehow but i dont want to damage anything by forcing it. ive tried accessing it from the rear of the speaker but didnt see anything helpful from that angle. anyone help would be much appreciated, i would much rather spend my 30 pounds on records and beer instead of postage

thanks!
p