When removing contexts, use context_load
to retrieve context object from the database, then context_delete
to remove it.
A specific example:
function example_update_7001() {
// 'example_one' is the value at /admin/structure/context in the Name column
$contexts = array('example_one', 'example_two');
foreach ($contexts as $context_name) {
// load the context from the DB
$context = context_load($context_name);
// context_load returns FALSE if the context doesn't exist
if ($context) {
context_delete($context);
}
}
}
You can also check the module is even enabled with module_exists('context')
around those lines.