in fig8 alternatively the conversion door 30 may be transported separately of the container 10 to the remediation site however it may be transported the conversion door 30 will be assembled upright so it occupies the space that was originally occupied by the door 10 5 a when the latter is in its closed condition the header assembly 40 is adjusted vertically to ensure that the vertical dimension of the conversion door 30 fits within the vertical dimension of the door frames 10 8 a 10 8 b once the vertical height of the door 30 is adjusted by means of the header assembly 40 the interior latches 33 may be pivoted into their latched condition see fig6 the door 10 5 b may remain in its opened condition until all remediation equipment and or environmentally damaged articles are positioned within the internal chamber 10 7 following which the door 10 5 a may be pivoted into its closed and latched condition as shown in fig9 to thereby establish the conversion of the container 10 into the remediation unit 20 the various ports 32 34 and or 36 may then be coupled to ducts and appropriate remediation equipment in the manner previously described following remediation the door 10 5 b may again be opened to allow the remediated articles to be removed from the internal chamber 10 7 additional.