Replace waste toner tank Does it mean that the toner is already used

Open your user manual.

Or get one - go to google or samsung.

The life of the waste toner container unit is approximately 1,250 pages for full color 5% image printing or 5,000 pages for black printing. When the life span of the waste toner container has expired, Replace/Install Waste Toner Tank appears on the display of the control panel,
indicating the waste toner container needs to be replaced. Otherwise your printer stops printing.

To replace the waste toner container:

1 Turn the machine off, then wait a few minutes for the machine to cool.

2 Open the front cover.

3 Pull the waste toner container out of the machine using its handle.

--- above from manual, following is my paraphrasing due to lack of pictures ---
4. remove the container cap from the back side and cap the opening

5. take the new waste container out of its package

6. install the new waste toner container.

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You may wish to TRY EMPTYING the waste toner, but you will find toner is the messiest and possibly dangerous (inhallation, etc) stuff you've worked with. it is an extremely find powder and can cause an awful mess and is best disposed of by capping and replacing the container with a new one (shop around to find them).

DO NOT attempt to vacuum up toner - just my personal opinion - I suspect many vacuums may not have fine enough "bags" to capture this intentionally very fine dust. BUT Toner vacuums do exist and some "may" work.

I emptied the waste toner container in my Samsung CLX3175FN and then replaced it. Now my printed pages have a one inch 'smudge' down the center of the page. any suggestion

Please you change your printer drum unite in wast toner. wast toner is in the drum unite full over used toner