The question is, why would you want to do that? Does it hurt you in any way, shape or form to have an extended partition?
Because unless you have a specific reason to do so, there is no harm in using an extended partition. In fact, it might be of advantage to just stick with it, in case you want to divvy up the space in more than 4 partitions (MBR partition scheme) later.
The answer depends on wether you have important data on that “member” or not. The “member” by the way is called a logical volume.
If there is no important data on it, you can just remove everything. You might have to remove the logical volume first and then the extended partition. Then you can just create another primary partition.
If there is still important data on it, you are going to lose it while removing and recreating the partition. So, your best option is probably going to be, to temporarily transfer the data to another drive, then remove the partitions, then move the data back.
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