In the pages panel, I clicked on the menu then selected "Override all master page items". I was then able to select the guides I needed to remove and hit delete.
(Note) This was a document I received from a colleague which required editing so you can understand my frustrations when trying to remove guides I hadn't placed there myself. I figured I'd keep this question up as future reference for anyone else having this issue.
Better to remove the guide from the master page, if you really wan them removed. But why not just hide them?
I did just that!
Hiding them removes everything - margins, gutter, bleed - I just wanted the guides gone that had been put there previously by the person who had worked on the document before me.
I didn't realise the guides had been added to the master page which then made them a permanent feature on every other page where they didn't need to be. So when I tried to remove them it became a bit of an issue!
Thank you for your response.
Overriding doesn't remove them from the master page, so they'd be active on other pages, and overriding all objects is not a good strategy for many reasons.
I had the same problem. All Layers were unlocked, Master Pages had no guides, Delete All Guides in Spread didn't delete them. Nothing worked.
Solution: Double Click the layer in the Layers palette for Layer Options ... There's a check box. "Lock Guides" ... Uncheck it.
There are two type of guide in indesign.
First one is, as generally used, just GUIDE. This guide is created in the Layout > Create guides, and so on....
Second one is, I think this may be the main reason of many questions which saying "cann't delete guide!", DOCUMENT COLUMN GUIDE. This guide is created when you first initialize your document or you can setup this in the Layout > margin and columns. The minimum value is 1, because the whole page itself is a column.
So, when you struck in problem with guides, please check the document column guide number. If you wanna make your page clear, setup that value as 1.
JFYI, when you go to the View > Grid & Guides, there are two guide view options. "Lock guides" and "Lock column guides" As I already mentioned, this lock options is for the each type of guide.