This is from wiki with German methods.
Bolt-on seats
Several clubs adapt their grounds to UEFA all-seater requirements by bolting temporary seats to the steps of otherwise essentially conventional terraces and removing the crush barriers. After the UEFA match, the seats are then removed again and the barriers put back. Stadia that operate in this way include those of Schalke 04, Borussia Dortmund and Borussia Mönchengladbach.
Fold-away seats
A small number of clubs adapt to the UEFA requirements by using seats that fold away under aluminium terrace steps. For domestic games such areas look like conventional terraces with intermittent crush barriers. For UEFA games the barriers are removed, the aluminium steps folded back and the seats flipped up. After the UEFA game, the procedure is reversed. German clubs using fold-away seats are Hamburg SV, VfB Stuttgart and Fortuna Düsseldorf.
Rail seats
Rail seats in Klagenfurt, Austria
Almost half of the top-flight Bundesliga clubs convert standing areas to all-seater configuration by using rail seats. Each metal seat is incorporated within a robust metal frame that forms a waist-high rail for the spectators in the row behind. These seat frames are installed on a permanent basis with the same spacing as standard seats. The frames interlock to form a continuous high-strength rail along the full length of each row. Rail heights vary between 90 and 115 cm.[16] For domestic games the seats remain locked flush between the uprights of each frame, thus providing accommodation and maximum space for standing fans between rows of the waist-high rails. Prior to UEFA games, the seats are unlocked, thus transforming the area into all-seater configuration. After the UEFA game, the seats are locked again in the upright position ready for use by standing fans at the next domestic match. German clubs using rail seats include Werder Bremen, Hamburg SV, VfL Wolfsburg, Hannover 96, TSG 1899 Hoffenheim, VfB Stuttgart, Bayer Leverkusen and Borussia Dortmund.
Standing at seats
The Olympic Stadium in Berlin is an all-seater stadium.[citation needed] Standing at domestic games is permitted – and expected – in front of seats in designated standing areas. One standing fan is permitted per seat space. The Allianz Arena in Munich was originally built as an all-seater stadium with standing allowed – and expected – in front of seats in designated standing areas. Approximately 30% more fans are permitted in these areas when used for standing. This is possible due to the considerable depth of the rows in the Allianz Arena. The seats in two blocks of the home 'curve' are removed for domestic games to allow standing in a more open space.[citation needed] For UEFA games these seats are bolted back in place.
Its possible, the FA and Government just need the b**** to give it a go at one or two grounds as a trial.