Doc Marten Steel Toe Cap 10 eye Boots size 5 (EU38) Brand new never worn +

Hi, I bought these boots then realised that they were too big for me. I paid 65 for them will accept 45 ono Or will swap for size 4 EU37 in same condition. Or why They have never been worn and are in brand new condition save 20 on new price. Below is the decription Iconic Dr. Martens 10-eye safety boot with hard wearing air-cushioned sole unit and Industrial strength leather. •Industrial corrected grain leather •Safety toe cap which conforms to and exceeds European Standard •Industrial strength cord laces •Foam backed PVC heel sock •Air-cushioned PVC sole •These shoes are heat-sealed then stitched •Slip resistant rating: SRA •STANDARD: EN ISO 20345: SB E