Complex sentence: Gretna did not play at their home stadium Raydale Park as it did not meet the SPL stadia criteria of 6,000 and instead used Motherwell's Fir Park for all but one of their games; that match was at Livingston's Almondvale Stadium.
Split into simpler sentences: Gretna did not play at their home stadium Raydale Park as it did not meet the SPL stadia criteria of 6,000. Gretna instead used Motherwell's Fir Park for most of their games, but also played one match at Livingston's Almondvale Stadium.