Summarize:

Launch the Flickr website in your web browser and sign in with your username and password. Your photos are available in two different areas: Click "Camera Roll" to view all of your photos. Clicking a photo will add it to the "pile" of photos to be downloaded, shown at the bottom of the screen. To add an entire batch of photos to the download pile, click "Select All" next to the date the photos were added. If you use Flickr albums to store your photo and want to download an entire album, click "Albums," then select an album to download. Now you'll be downloading the photos you've added to the download pile. A different pop-up message will appear depending on how many photos you've selected: If you've selected one image, the message will say "Download 1 photo." Click the message box to choose where to save it on your computer. The download will begin. If you've selected multiple photos (or an entire album), the message will say "Download zip." Click the message to create a single zip file, then choose a folder to save your zip file. When the download is complete, locate the zip file. Windows users, double-click the zip file, then click "Extract" to unpack the images. Mac users can double-click the zip file to extract the images to the current folder.
Log into your Flickr account. Select the photos you want to download. Click "Download" at the bottom of the screen.