I have a clio 98 s, some delightful chap has decided to put superglue in my drivers door lock and seized it.Is there anything I can put in to dissolve the glue or does the barrel have to be replaced,thanks.
Not a nice thing to do at all (I bet you had some choice words...).
I believe it can be dissolved, but the problem is that any solvent spilled may do your paintwork some major harm, plus, if you can immerse the barrel in the solvent, it will clear more quickly/completely.
Therefore, it would be best to remove the barrel from the door (which will require removal of the interior trim panel). This is usually held in place with a mixture of screws and torx-headed bolts found in the door pull, door release lever housing and around the perimeter of the trim. This will, once removed give access to the barrel, which is usually held in place with a clip.
I would suggest a powerful solvent such as acetone (nail varnish remover), or I'm sure most hardware outlets will stock a dedicated chemical for this purpose.
Once it is clear of all traces of the glue, give the mechanism plenty of lubrication, and possibly some grease to prevent the moving parts from seizing up.