By opening your own profile you will find this bar in the upper area of your screen:
Clicking on the option Photos leads you to your own photo gallery. That contains all your uploaded pictures and applied photo foulders.
This button opens an window: where you can choose the pictures you want to upload.
As an alternative way you can click on in the left sidebar and select . A window for the further upload-selection will open again.
If you would like to delete a picture from your profile und need to select it by clicking on it in your photo gallery. On the lower left corner of the opening Imageselection you find the 'delete-button':. The picture will be deleted after clicking this button.