These modules have a design fault - if the module has failed, then buy a NEW one.
I have found them for £140 locally, which comes with module and burner. There are stocks around, so look in your camping shops - at mine, it was only £20 more than it cost to get one online.
The design fault is to do with the seal, which can be breached by the pilot flame, causing damage to the module. If you remove the outer vent, there is likely to be a large amount of coking behind the shield.
Replace the whole unit, as these can cause fires inside if left or allowed to continue.