Dyson DC04 Switch/Lead

After seeing the answer to this many times my lead has now failed. Dyson want 50 to send an engineer, yeah right! I can see the slot people talk about for removing but has anybody any info on what to use to get down the slot? I have tried a small jewellers driver and some jet cleaners but don't know if they are reaching the 'locking tab'. What length does the implement need to be and am I likely to have anything in my garage suitable?
Many ythanks

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.